Most of the commercial washers use a high temp mineral spirits...140 degree. Safety Kleen adds a soap/additive package but is extremely expensive. Find a local dry cleaner supply store...you should be able to buy 140 mineral spirits in 5 or 10 gallon lots at a reasonable price. Note, this is still flammable so be careful with the location of your washer in relation to hot water heaters/furnaces. Chuck